Google Web Toolkit - How to prevent duplication of the records? - gwt

Question

I am new in GWT. I am trying to use the cell table to do this. Here is my questions:
Name Gender
Ali M
Abu M
Siti F
page 1
Name Gender
Siti F
Noor F
Ahmad F
page 2
I use simple pager to do the paging function. Everything is ok except next page.
When i click next page, siti record appear 2 times.
How to prevent the name Siti not appear in page 2? Below are my code:
private static class Contact{
private final String name;
private final String gender;
public Contact(String name, String gender){
this.name = name;
this.gender = gender;
}
}
private static final List<Contact> CONTACTS = Arrays.asList(
new Contact("Ali","M"),
new Contact("Abu","M"),
new Contact("Siti","F"),
new Contact("Noor","F"),
new Contact("Ahmad","M")
);
public void onModuleLoad(){
final CellTable<Contact> table = new CellTable<Contact>();
table.setPageSize(3);
TextColumn<Contact> nameColumn = new TextColumn<Contact>(){
#Override
public String getValue(Contact object) {
return object.name;
}
};
TextColumn<Contact> genderColumn = new TextColumn<Contact>(){
#Override
public String getValue(Contact object) {
return object.gender;
}
};
table.addColumn(nameColumn, "Name");
table.addColumn(genderColumn, "Gender");
AsyncDataProvider<Contact> provider = new AsyncDataProvider<Contact>(){
#Override
protected void onRangeChanged(HasData<Contact> display) {
int start = display.getVisibleRange().getStart();
int end = start + display.getVisibleRange().getLength();
end = end >= CONTACTS.size() ? CONTACTS.size() : end;
List<Contact> sub = CONTACTS.subList(start,end);
updateRowData(start,sub);
}
};
provider.addDataDisplay(table);
provider.updateRowCount(CONTACTS.size(), true);
SimplePager.Resources pagerResources = GWT.create(SimplePager.Resources.class);
SimplePager pager = new SimplePager(TextLocation.CENTER, pagerResources, false, 0, true);
pager.setDisplay(table);
Please help me to solve this problem. Thanks.

Answer 1

You have faced most probably the gwt last page problem, described in the linked questions:
GWT - celltable with simple pager issue
SimplePager row count is working incorrectly
The solution here is to set:
setRangeLimited(false)
and the last page is paged correctly, ie. it contains only Noor and Ahmad.
So in conclusion: actually no duplication is present here, but a bug on pagination in case of the last page. You will observe the same behavior with also other amounts of data, but on my view point it would be always a last page issue only.